In fabricating disposable garments using a continuous web to form discrete garment blanks, and optionally the garments, themselves, it is known to incorporate elastic threads, both stretched and unstretched, into the garment structure, in both the with machine direction and the cross machine direction. When stretched elastic threads are incorporated into the web in the cross machine direction, the elastic threads urge retractive forces on the web in the cross machine direction, tending to reduce the width of the web.
In addition, to the extent the elastic extends across the crotch portion of the garment being fabricated, the cross-crotch elastics urge a bunching up of the material extending across the crotch, whereby the crotch portion of the garment will not lie flat against the body of the user.
Further, to the extent portions of the workpieces are to be bonded to each other with bonds extending in the cross machine direction, it is desirable to have substantial dwell time at the bonding station in the apparatus, in order to effect fabrication of the requisite bonds.
Thus it is an object of this invention to provide methods and apparatus for relieving and/or otherwise nullifying the retractive effect of elastics incorporated in the web in the cross machine direction.
It is a further object to provide methods and apparatus for severing the cross crotch elastics.
It is still a further object to provide apparatus for relieving the stretch in the elastics as the elastics feed into the web at the locus that forms the crotch of each workpiece, and for exerting a stretched condition on the elastics as the elastics feed into the web at loci not forming the crotch of the respective workpieces.
It is another object to provide methods and apparatus for treating cross crotch elastics in order to avoid having the cross crotch elastics causing the crotch to bunch up on the user.
Still another object is to provide method and apparatus for placing crotch elastics on each workpiece to extend in a transverse direction across the web, such that opposing portions of the crotch elastics extend to, and coact with, front and back leg elastics in the garment.
Another object is to use friction surface such as obtained with plasma coatings on processing rolls, optionally with suction on the rolls, to stabilize the width dimension of the web after incorporating stretched elastics into the web in a direction transverse to the with machine direction.
It is yet another object to provide bonding apparatus and methods which provide for fabricating bonds in a direction transverse to the with machine direction, and to give substantially more dwell time for forming the bonds than applies as a workpiece passes a planar-type bonding apparatus, such as a plunge bonder.
Yet another object is to form such transverse bonds using a rotary carrying drum and energy application devices, preferably to apply ultrasonic energy to so form the bonds.